Steiner Navigator 7x50
If you look for marine binoculars the German Steiner company offers you two specialized series: the cheaper Navigator and the more expensive Commander. In both cases you deal with Porro prism 7x30 and 7x50 instruments, available with or without compass.
very solid and waterproof casing; very good correction of chromatic aberration; negligible distortion; moderate coma; sharp image across almost all field of view; low brightness loss of the image on the edge of the field of view
prism optical elements lack coating; truncated exit pupils; darkened on the very edge; inside of the tubes leaves a lot to be desired